1. Field of the Invention
The present invention relates to a stator core and a motor device including the same, and more particularly, a stator core having an improved stator core shape to maximize current characteristics and motor efficiency, and a motor device including the same.
2. Description of the Related Art
Electric motors are devices that convert electrical energy into mechanical energy, and may be classified into various kinds according to types of power being supplied thereto, driving methods, rotor types and exterior structures associated with frames, brackets and the like. Furthermore, the electric motors, classified as above, may be re-classified according to insulating methods, bearing types, outputs, number of rotations, voltage, frequency and the like.
Among those motors, a spindle motor installed inside an Optical Disk Drive (ODD) rotates a disc so that an optical pickup unit moving in a linear direction can read data recorded on the disc.
Disk drives are applicable to portable multimedia devices such as laptop computers that are handy to carry and use anywhere and anytime. There has been a demand for thinner disk drives to cope with a current trend toward smaller portable media devices.
Most spindle motors, currently being installed in disk drives, have a stator core produced by the following processes: stacking a plurality of core sheets, pressed silicon steel plates, forming an insulating layer on the resultant stack and winding a coil therearound. In this case, an electromagnetic force, generated by current flowing in the wound coil, acts as the cause of rotational torque of spindle motors.
However, as a motor is driven according to the related art, eddy current is increasingly generated, causing defective motor operation, and Back Electro Motive Force (Back-EMF) waveforms are rendered sharp, degrading the efficiency of the motor.
Moreover, the stator core provided as a stack of cores interrupts magnetic flux from a magnet to the cores, due to the stacked structure thereof. This may accelerate magnetic saturation in the ends of the cores, thereby degrading motor efficiency.
Therefore, an optimized design for a stator core is being currently demanded in order to minimize the loss of a motor while ensuring motor characteristics.